System and method for heating passenger cabin with inverter waste heat boosted by a heater

1. A vehicle comprising:

a heating ventilation and air conditioning (HVAC) unit including:

a housing defining an air inlet, a cabin vent, and an exterior vent that vents air outside of the vehicle,

a blend door disposed downstream the exterior vent and upstream the cabin vent, the blend door including a first position in which the air inlet and the cabin vent are in fluid communication and a second position in which the air inlet and the cabin vent are not in fluid communication,

a heater core disposed within the housing between the air inlet and the blend door, and

an electric heater disposed within the housing downstream of the blend door; and

a coolant system including conduit arranged to circulate coolant through the inverter and the heater core.

2. The vehicle of claim 1 , wherein the HVAC unit further includes a first blower disposed within the housing upstream of the heater core and a second blower disposed within the housing downstream of the blend door.

3. The vehicle of claim 1 , wherein the coolant system is valveless.

4. The vehicle of claim 1 further comprising a controller programmed to, in response to cabin heating not being requested, actuate the blend door to the second position.

5. The vehicle of claim 1 further comprising:

a temperature sensor disposed within in housing downstream of the heater core and upstream of the electric heater, the sensor being configured to output a signal indicative of an air temperature; and

a controller programmed to:

in response to cabin heating being requested, actuate the blend door to the first position, and

in response to the air temperature being below a desired temperature, energize the electric heater.